dlls/msvcrt/lock.c

   1 /*
   2  * Copyright (c) 2002, TransGaming Technologies Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  17  */
  18
  19 #include <stdarg.h>
  20
  21 #include "wine/debug.h"
  22 #include "windef.h"
  23 #include "winbase.h"
  24 #include "mtdll.h"
  25
  26 WINE_DEFAULT_DEBUG_CHANNEL(msvcrt);
  27
  28 typedef struct
  29 {
  30   BOOL             bInit;
  31   CRITICAL_SECTION crit;
  32 } LOCKTABLEENTRY;
  33
  34 static LOCKTABLEENTRY lock_table[ _TOTAL_LOCKS ];
  35
  36 static inline void msvcrt_mlock_set_entry_initialized( int locknum, BOOL initialized )
  37 {
  38   lock_table[ locknum ].bInit = initialized;
  39 }
  40
  41 static inline void msvcrt_initialize_mlock( int locknum )
  42 {
  43   InitializeCriticalSection( &(lock_table[ locknum ].crit) );
  44   lock_table[ locknum ].crit.DebugInfo->Spare[0] = (DWORD_PTR)(__FILE__ ": LOCKTABLEENTRY.crit");
  45   msvcrt_mlock_set_entry_initialized( locknum, TRUE );
  46 }
  47
  48 static inline void msvcrt_uninitialize_mlock( int locknum )
  49 {
  50   lock_table[ locknum ].crit.DebugInfo->Spare[0] = 0;
  51   DeleteCriticalSection( &(lock_table[ locknum ].crit) );
  52   msvcrt_mlock_set_entry_initialized( locknum, FALSE );
  53 }
  54
  55 /**********************************************************************
  56  *     msvcrt_init_mt_locks (internal)
  57  *
  58  * Initialize the table lock. All other locks will be initialized
  59  * upon first use.
  60  *
  61  */
  62 void msvcrt_init_mt_locks(void)
  63 {
  64   int i;
  65
  66   TRACE( "initializing mtlocks\n" );
  67
  68   /* Initialize the table */
  69   for( i=0; i < _TOTAL_LOCKS; i++ )
  70   {
  71     msvcrt_mlock_set_entry_initialized( i, FALSE );
  72   }
  73
  74   /* Initialize our lock table lock */
  75   msvcrt_initialize_mlock( _LOCKTAB_LOCK );
  76 }
  77
  78 /**********************************************************************
  79  *     msvcrt_free_mt_locks (internal)
  80  *
  81  * Uninitialize all mt locks. Assume that neither _lock or _unlock will
  82  * be called once we're calling this routine (ie _LOCKTAB_LOCK can be deleted)
  83  *
  84  */
  85 void msvcrt_free_mt_locks(void)
  86 {
  87   int i;
  88
  89   TRACE( ": uninitializing all mtlocks\n" );
  90
  91   /* Uninitialize the table */
  92   for( i=0; i < _TOTAL_LOCKS; i++ )
  93   {
  94     if( lock_table[ i ].bInit )
  95     {
  96       msvcrt_uninitialize_mlock( i );
  97     }
  98   }
  99 }
 100
 101
 102 /**********************************************************************
 103  *              _lock (MSVCRT.@)
 104  */
 105 void CDECL _lock( int locknum )
 106 {
 107   TRACE( "(%d)\n", locknum );
 108
 109   /* If the lock doesn't exist yet, create it */
 110   if( lock_table[ locknum ].bInit == FALSE )
 111   {
 112     /* Lock while we're changing the lock table */
 113     _lock( _LOCKTAB_LOCK );
 114
 115     /* Check again if we've got a bit of a race on lock creation */
 116     if( lock_table[ locknum ].bInit == FALSE )
 117     {
 118       TRACE( ": creating lock #%d\n", locknum );
 119       msvcrt_initialize_mlock( locknum );
 120     }
 121
 122     /* Unlock ourselves */
 123     _unlock( _LOCKTAB_LOCK );
 124   }
 125
 126   EnterCriticalSection( &(lock_table[ locknum ].crit) );
 127 }
 128
 129 /**********************************************************************
 130  *              _unlock (MSVCRT.@)
 131  *
 132  * NOTE: There is no error detection to make sure the lock exists and is acquired.
 133  */
 134 void CDECL _unlock( int locknum )
 135 {
 136   TRACE( "(%d)\n", locknum );
 137
 138   LeaveCriticalSection( &(lock_table[ locknum ].crit) );
 139 }